Taltirelin alpha crystal form preparation method

The present invention relates to crystal form preparation, specifically to a new taltirelin alpha crystal form method, which specifically comprises: dissolving taltirelin in a solvent under a stirring state to obtain a taltirelin solution, wherein the solvent comprises, by volume, 0.5-15% of an aqueous medium and the balance of tetrahydrofuran, and the temperature is 40-70 DEG C; and cooling the obtained taltirelin solution so as to crystallize, and separating and drying to obtain the taltirelin alpha crystal form crystal. According to the present invention, the method of the present invention has characteristics of good process stability, strong operability, high yield and the like; the free water content in the obtained product is low, wherein the water content is 14.5-15.3% when the water content of the alpha crystal form is determined by using the Karl Fischer method while the water content is generally 13.0-17.0% of the alpha crystal form prepared by using the method reported in the prior art, and mainly the drying process is difficult to control so as to cause the wide range, such that the melting range is increased.